/*********************************************************************
  C201 Computer Programming II
  Fall 2006
  Dana Vrajitoru &

  The data structure storing linked lists.

**********************************************************************/
#include <iostream>
using namespace std;
#include <ctype.h>

#include "list.h"

// List traversal function. It prints all the elements of the list.
void Output_list(Node_ptr front)
{
  if (!front) // if (front == NULL)
    cout << "The list is empty" << endl;
  else {
    Node_ptr p = front;
    while (p) {
      // Output the content of the node and a space.
      cout << p->word << ' ';
      // Move the pointer to the next node.
      p = p->next;
    }
    // Output an endl at the end of the list.
    cout << endl;
  }
}

// Returns the number of nodes in the list.
int Count_nodes(Node_ptr front)
{
  Node_ptr p = front;
  int count = 0;
  while (p != NULL) {
    ++count;
    p = p->next;
  }
  return count;
}

// Inserts a new node at the front of the list. The front is a
// reference parameter because the new node becomes the front of the
// list.
void Insert_front(Node_ptr &front, string s)
{
  Node_ptr n = new Node;
  n->word = s;
  n->next = front;
  front = n;
}

// Removes the front node of the list. If the list is empty, it
// returns false.
bool Remove_front(Node_ptr &front)
{
  if (!front)
    return false;
  else {
    Node_ptr temp = front;
    front = front->next;
    delete temp;
    return true;
  }
}

// Deletes the entire list
void Delete_list(Node_ptr &front)
{
  Node_ptr p = front;
  while (front) {
    front = front->next;
    delete p;
    p = front;
  }
}

// Returns a pointer to the last node in the list. It's a special list
// traversal that must stop before the pointer scanning the list
// becomes NULL.
Node_ptr Last_node(Node_ptr front)
{
  if (!front)
    return NULL;
  else {
    Node_ptr last = front;
    while (last->next != NULL)
      last = last->next;
    return last;
  }
}

// Searches for a particular string in the list. If the string is
// there, it returns a pointer to the node that contains it. If not,
// it return NULL.
Node_ptr Search(Node_ptr front, string s)
{
  if (!front)
    return NULL;
  else {
    Node_ptr loc = front;
    while (loc != NULL) {
      if (loc->word == s)
	return loc;
      loc = loc->next;
    }
    return NULL;
  }
}

//****************** Homework functions ******************

// Insert the string as a new node at the back of the list.
void Insert_back(Node_ptr &front, string s)
{
  // To be implemented by the students.
}

// Returns a string obtained by the concatenation of the words in all
// the nodes of the list in order and separated by spaces.
string Concatenate(Node_ptr front)
{
  // To be implemented by the student.
  return "";
}

// Returns a pointer to the node number i in the list, where the first
// node is at position 0. If the list has less than i+1 nodes, it
// returns NULL.
Node_ptr Access_index(Node_ptr front, int i)
{
  // To be implemented by the students.
  return NULL;
}

// Converts the first letter of every word in the list to uppercase.
void Toupper_all(Node_ptr front)
{
  // To be implemented by the students.
}

// Converts the first letter of every word in the list to lowercase.
void Tolower_all(Node_ptr front)
{
  // To be implemented by the students.
}

// Reverses the list. It will most likely create a new list containing
// the same nodes as the list starting from front but in reverse
// order, then delete the old list and store the address of the first
// element of the new list in the pointer front.
void Reverse_list(Node_ptr &front)
{
  // To be implemented by the students.
}